This invention relates to a shock absorber and more particularly to an improved and simplified ride control type of shock absorber.
A type of shock absorber has been proposed for vehicles such as automobiles and motorcycles wherein the damping force can be varied to suit either the rider or driver's desires or road conditions. This is done by providing an electrically operated pilot valve in the piston of the shock absorber. This pilot valve is electrically controlled to vary the pressure at which it opens and, accordingly, the damping characteristics of the shock absorber.
In addition to the pilot valve and its actuator, the piston must carry other valves and passages for its operation. Since all of these components are formed within the piston, prior art constructions have been quite complicated and difficult to manufacture and assemble. Also since all of the components are mounted internally within the piston, with prior art type of constructions it has not been possible to test the individual components before assembly. The disadvantages of this are believed to be obvious.
It is, therefore, a principal object to this invention to provide an improved shock absorber that can having its action externally controlled and yet which is simple in construction and assembly.
It is a further object of this invention to provide a controlled shock absorber that is manufactured from a number of sub-components which may be easily inserted into the piston of the shock absorber as respective units.
It is a further object to this invention to provide an improved shock absorber assembly of this general type.
In connection with shock absorbers of the type described, the pilot valves has heretofore comprised a spool valve that operates to control the flow between two chambers and, accordingly, the action of the shock absorber. However, the use of spool valves has a number of disadvantages. Specifically, the port and spool gives a delay in action and also if attempts are made to reduce this delay then leakage and reliability become problems. It has also been proposed to replace the spool valve with a poppet valve but the poppet valve has a problem in that the head of the poppet valve overlaps the valve seat and causes flow restrictions and also action on the valve which tends to cause it to be drawn back to its valve seat or vibrate.
It is, therefore, a still further object to this invention to provide an improved valve for a shock absorber which has the advantages of a poppet valve without the normal disadvantages of a poppet valve.